IDNet have made a couple of tweaks to the configuration on the free webspace.
Going into the parent directory without putting up an index page will now display a permission denied message, rather than listing the contents of the webspace. This was a measure put in place after they had multiple complaints about privacy and security.
Also, in an effort to standardise the way the server works, the correct format for the index page has to be index.html (all in lower case) anything else will result in the aforementioned permission denied message.